Here are a couple of ideas:
- Loop Habit has the ability to save a full backup. Maybe try setting up your habits, add some fake data, and generate the backup. Open the backup file in a text editor and see whether you can infer the structure. If so, just reformat your old data to match that structure and then import that "hacked" backup file back into Loop.
- Loop Habit says it can import backup files from Tickmate, Habitbull, and Rewire as well. Similar to the above idea, if you can reformat your saved data to match one of those formats you should be able to import it into Loop.